Memory speed woes

Reviewers praised the C19 based Asus P5ND2-SLI Deluxe although these same sentiments weren't echoed within the Overclocking and PC-Enthusiast forums concerning any C19 based motherboard. Initially I found a marked difference between memory settings made in BIOS and memory speeds as indicated by OEM monitoring/benchmarking utilities. One of the first things I do when testing a product is to verify settings made in the BIOS using widely accepted utilities such as CPU-Z, SiSoftware Sandra and Lavalys Everest Home Edition. In each case memory speeds were displayed at 1/2 the frequency (or data rate) set in the BIOS. This in conjunction with some truly extraordinary memory dividers had me jumping up and down to hit the reset button like a three-legged dog in a flea scratching contest. The screenshot below exemplifies what I was seeing.



Note the CPU-Z crop on the left indicates an 8:5 divider and a memory speed of 168.8MHz. On the right running Sandra Memory Bandwidth benchmark resulted in a 6754MB/s score. However looking down to the chipset/FSB/memory specs the FSB is accurate at 4x 270MHz (1080Mhz data rate), yet the memory speed below at 2x 168MHz (336MHz data rate) belies the score above. To exemplify this issue is in fact related to the software utilities mentioned above and not Asus C19 boards in particular I've provided a screenshot using Gigabyte's GA-8N-SLI Royal motherboard and CPU-Z.



It seems Gigabyte designers have got it right as Easy Tune 5 reads the memory frequency correctly. Regardless of the board used CPU-Z seems to struggle with the C19, misreading memory frequency by exactly 1/2 (multiply x4 for the actual memory speed). The divider on the nVIDIA SLI chipset is not manually adjustable (at least in usual manner) instead it changes in relation to the FSB, in this case 225FSb or 900MHz (QDR). The Sandra result above at 5332MB/s while running the same CPU and Corsair 5400UL memory is due to a lower FSB speed and higher CAS Latencies.

I've brought attention to these issues for several reasons. I was troubled to discover prior to my Corsair 5400UL article I was unable to find any mention of this after reading just about every Review pertaining to memory tested on C19 chipset based boards and/or reviews pertaining to C19 boards. I wanted to assure any P5ND2-SLI owners or anyone having purchased a C19 based motherboard they need not be overly concerned with CPU-Z or Sandra "misreading" memory speeds. Simply multiplying (x2 or x4) will give the correct frequency. The authors of CPU-Z and Sandra contacted me immediately after my Corsair 5400UL review and are currently re-testing to resolve the issue. nVIDIA's cooperation would be appreciated.


C19 thermal characteristics



This chipset runs hot, I measured almost 50*C placing a thermal-sensor on the heatsink base! I was surprised to see a passive heatsink on the North Bridge perform as well as it did. Despite the width of this passive beast which belies the C19 chipset's size, the C19 is no larger then Intel's 925XE North Bridge.



The architecture beneath the surface is where Intel and nVIDIA are markedly different. In the computer industry connotations of "size matters" are juxtaposed.



The PCI slots supporting SLI functions are labeled PCIEX16_1 and PCIEX16_2, PCIEX16_1 is a true 16X throughput, but only in single card mode. In single card mode two cards can be used, however PCIEX16_1 will run at 16X while PCIEX_2 will run at 1X. In SLI mode each slot operates at 8X. Utilizing both slots in Multi-Monitor, RAID or LAN card mode PCIEX16_1 runs at 8X and PCIEX16_2 can run at 8x, 4x, 2x, or 1x depending on the card in that slot. In SLI mode an additional Molex must be fed into the board just above PCIEX16_1.



To enable or disable SLI mode Asus EZ Select card must be installed in one of two positions. At the base of the card two small clips must be spread outward releasing the card. Juxtaposing and re-inserting the card based on edge label will determine Single Video Card or Dual Video Card as seen below.



Regardless of card type a red LED located adjacent to the SLI Molex will illuminate if the end-user overlooks connecting an additional molex when in SLI mode. I tested this feature with Gigabyte 6800GT's and Asus EN6600GT's in both cases the light would illuminate (in standby prior to power-up) if the molex were un-plugged.



Asus P5ND2-SLI Deluxe accommodates Intel Socket-775 architecture, which includes Pentium Extreme Edition, Pentium D, Pentium 4 and Celeron CPUs. The board also supports EM64T, EIST, and Hyper-Threading.



From this angle the capacitance (storage) surrounding the socket indicates nVIDIA was sure to provide plenty of storage for the power hungry Prescott. While the board can accommodate a more efficient Celeron, peak power must be considered.



The P5ND2-SLI Deluxe accommodates up to 8GB of non-ECC DDR2 from DDR2-533 to DDR2-667/800. A small inconvenience is the slots are difficult to access using larger nVIDIA graphic cards. The ATX power connector placement is also visible below as well as the floppy and primary IDE at the very bottom of the photo.



Storage: personally I tend to minimize storage because it's not as "sexy" as the overclockable devices. That is, until I'm waiting for a file to open. Regardless of ones RAM compliment, most files/programs must first be retrieved from your HDD, even DASP can't predict what program you'll use next. The ITE IT8712F-A is responsible for legacy "Super I/0" and can also serve to monitor HW (temp, volt etc.).



Primary Serial ATA storage is handled by the nVIDIA nForce South Bridge itself; MCP-04 can accommodate 2x Ultra DMA > 133 and 4x Serial ATA 3Gb/s as well as in RAID 0, RAID 1 RAID 0+1, RAID 5 for a total of 8 Multi RAID drives.



Additionally the P5ND2-SLI Dlx features the Silicon Image 3132 chip supporting 1x Internal and 1x External Serial-ATA 3Gb/s HDD's in RAID 0 and RAID-1



nVIDIA nForce-4 South Bridge features an Intel Edition Ggabit MAC with external PHY function shared the Marvelll Alaska 88E1111 Gigabit Ethernet transceiver (below).



In addtion the P5ND2-SLI Dlx also utilizes the Intel 8254OEM Gigabit LAN controller chip (below).



On-board sound is provided per Realtek's ALC850 an AC97' featuring four 16-bit two-channel DACs and a stereo 16-bit ADC. The chip offers 8-channel sound and all the accoutrements. It's simply amazing a chip this minute can handle all these functions? Although a far cry in quality from Burr Brown (now TI) audiophile grade DACs such as their PCM1704 24Bit /96Khz found in true high-end separates such as Wadia and Theta Digital. You haven't heard D/A conversion until you've heard Burr Brown DACs in a vacuum-tube output staged D/A converter.

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While this may seem un-important I found the P5ND2-SLi Dlx clearly labeled, for example its Front Panel connection pins which can be difficult to see unless your cable length allows connection outside of the case. A nice touch!



Finally at the heart of Asus AI Proactive software is the Winbond W83791SD H/W monitoring IC. The W83791SD features speech activation in compliance with the ASF (Alert Standard Forum who knew?).



Onto testing where we will discuss Asus AI in further detail ->